Different concepts for floor and underfloor structures are known in motor vehicle body construction. Two lateral frame rail arrangements are most often provided in the area of the passenger cabin, and are joined together by means of individual cross members running in the transverse direction of the vehicle. A support frame made of these components can further be provided with a floor panel, which largely fills out the gap between the frame rails or cross members.
A transmission hump is most often to be provided centrally between the frame rail structures, which is either integrated as a single piece into the floor panel, or adjoined by individual floor panel sections separately joined with the transmission hump, in particular given a floor panel comprised of multiple parts.
For example, DE 102 32 841 A1 discloses a floor beam arrangement with a front floor cross member and two rocker panels arranged to the side of the vehicle body. Frame rails run between the rocker panels, and for their part proceed from the front end, extending toward the back under a floor panel that closes off the passenger cabin from below. A large profile cross section of the frame rails here abuts an end plate of the front floor cross member, after which a comparatively smaller profile cross section thereof runs under the floor panel, vertically offset.
Such frame rail arrangements comprised of frame rails and frame rail extensions typically are vertically offset in the longitudinal direction of the vehicle. Both during a laterally offset frontal collision and in the course of a pole test, which involves simulating the lateral impact of a motor vehicle against a tree, the longitudinal frame or rocker panel profile adjoining the latter can be exposed to considerable deformation, which is inwardly directed toward the passenger cabin. In addition, the frame rail arrangement can exhibit a tendency to tilt and also turn into the passenger cabin given its varying height profile in the longitudinal direction of the vehicle.
By contrast, it is at least one object herein to provide a floor structure of a motor vehicle body with an improved structural rigidity and mechanical stability, which can possibly even be manufactured with a reduced body or vehicle weight. In addition, the floor structure is to enable an effective utilization of the installation space present in the floor or underfloor region of the motor vehicle, in particular the space-saving accommodation of other functional parts and vehicle components. The floor structure is also intended to improve the torsional and twisting stiffness of the vehicle body itself. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.